Karyotype, Sex Determination, and Meiotic Chromosome Behavior in Two Pholcid (Araneomorphae, Pholcidae) Spiders: Implications for Karyotype Evolution

There are 1,111 species of pholcid spiders, of which less than 2% have published karyotypes. Our aim in this study was to determine the karyotypes and sex determination mechanisms of two species of pholcids: Physocyclus mexicanus (Banks, 1898) and Holocnemus pluchei (Scopoli, 1763), and to observe sex chromosome behavior during meiosis. We constructed karyotypes for P. mexicanus and H. pluchei using information from both living and fixed cells. We found that P. mexicanus has a chromosome number of 2n = 15 in males and 2n = 16 in females with X0-XX sex determination, like other members of the genus Physocyclus. H. pluchei has a chromosome number of 2n = 28 in males and 2n = 28 in females with XY-XX sex determination, which is substantially different from its closest relatives. These data contribute to our knowledge of the evolution of this large and geographically ubiquitous family, and are the first evidence of XY-XX sex determination in pholcids

Chromosome Congression by Kinesin-5 Motor-Mediated Disassembly of Longer Kinetochore Microtubules

During mitosis, sister chromatids congress to the spindle equator and are subsequently segregated via attachment to dynamic kinetochore microtubule (kMT) plus-ends. A major question is how kMT plus-end assembly is spatially regulated to achieve chromosome congression. Here we find in budding yeast that the widely-conserved kinesin-5 sliding motor proteins, Cin8p and Kip1p, mediate chromosome congression by suppressing kMT plus-end assembly of longer kMTs. Of the two, Cin8p is the major effector and its activity requires a functional motor domain. In contrast, the depolymerizing kinesin-8 motor Kip3p plays a minor role in spatial regulation of yeast kMT assembly. Our analysis identified a model where kinesin-5 motors bind to kMTs, move to kMT plus ends, and upon arrival at a growing plus-end promote net kMT plus-end disassembly. In conclusion, we find that length-dependent control of net kMT assembly by kinesin-5 motors yields a simple and stable self-organizing mechanism for chromosome congression

To know or not to know:should crimes regarding photographs of their child sexual abuse be disclosed to now-adult, unknowing victims?

This paper considers the unexplored question of whether unaware crime victims have rights or interests in knowing and not knowing information pertaining to the crime(s) committed against them. Our specific focus is on whether crimes regarding abusive images (AI) should be disclosed to now-adult victims of child sexual abuse who feature in them. Because these issues have not been addressed in the victimology or criminological literature, we utilise literature in another discipline - health care ethics and law - to inform our analysis. Through engaging with the debate on the right to know and not to know information concerning one’s genetic status, we develop a conceptualisation of the issues regarding unknowing AI victims. A rights-based conceptualisation proves to be largely inappropriate; we contend that, instead, it would be more productive to look to unknowing AI victims’ interests. We argue that the interests at stake are grounded in autonomy and/or spatial privacy, and that in order to find a way to resolve the disclosure dilemma, these interests must be considered alongside consequentialist concerns; disclosing information regarding AI could empower now-adult victims but could well cause them (further) harm. Finally, we consider the implications of our analysis for victimology

Pomiar zanieczyszczenia powietrza atmosferycznego SO2 z zastosowaniem porostów i próbników pasywnych

It is possible to analyse a negative impact on environmental air quality by using living organism’s bio indicative reaction to pollutants. Lichens (Lichenes L.) are very sensitive to gaseous pollutants so may be used to evaluate air pollution. Thirteen points in Raseiniai district were selected for measurements of sulphur dioxide concentrations in ambient air using lichens and passive samplers for comparing. Measured values of SO2 concentrations were compared with limit values set for this pollutant in ambient air according to 2008/50/EC and 2000/69/EC directives. SO2 concentrations determined with lichens was bigger than determined with passive samplers, but in both cases, they were low and did not reach permissible limitary values in ambient air. Further from, the main pollution sources (main industrial enterprises in Raseiniai district) values of SO2 concentration in the ambient air gradually decreased. Average SO2 concentrations in ambient air of Raseiniai district did not reach permissible limitary values set for ambient air (125 μg/m3) during the study period in August 2016. The study results show that the highest concentration of SO2 in the ambient air determined applying lichens was in Raseiniai district (41±2.0 µg/m3) and its surroundings (Gabšiai (40±2.0 µg/m3), Andrušaičiai (41±2.0 µg/m3) and Gruzdiškės (39±2.0 µg/m3). The study results show that the highest concentration of SO2 in the ambient air determined applying passive samplers was in Raseiniai district (5.1±0.50 µg/ m3) and its surroundings (Gabšiai (4.0±0.39 µg/ m3), Andrušaičiai (4.3±0.41 µg/ m3) and Gruzdiškės (3.5 µg/ m3)). The lowest concentration of SO2 was determined in the Nemakščiai and Viduklė elderships where, respectively, the concentration of SO2 was 4±2.0 µg/m m3 and 16±2.0 µg/m m3 determined applying lichens and 2.0±0.18 µg/m m3 and 2.7±0.26 µg/m m3 applying passive samplers. There were significant statistical relationships between measured SO2 concentrations with both methods when Pearson's correlation matrix was applied to the variables at a 95% confidence interval. A strong positive correlation (r = 0.84) between concentrations of SO2 measured with lichens and passive samplers indicates that lichens can be applied for approximation evaluation of SO2 concentrations in ambient air. The lowest concentrations in investigated elderships are influenced by the fact that they are distant from the major industrial enterprises and energetic objects.Możliwe jest przeanalizowanie negatywnego wpływu na jakość powietrza w środowisku poprzez zastosowanie bio-indykatywnej reakcji żywych organizmów na zanieczyszczenia. Porosty (Lichenes L. ) są bardzo wrażliwe na zanieczyszczenia gazowe, więc można je wykorzystać do oceny zanieczyszczenia powietrza. Trzynaście punktów w okręgu Raseiniai zostało wybranych do pomiarów stężenia dwutlenku siarki w powietrzu z użyciem porostów i próbników pasywnych dla porównania. Zmierzone wartości stężeń SO2 porównano z wartościami granicznymi ustalonymi dla tego zanieczyszczenia w powietrzu zgodnie w dyrektywach 2008/50/WE i 2000/69/WE. Stężenia SO2 określone za pomocą porostów porostów były wyższe niż uzyskane za pomocą próbników pasywnych, ale w obu przypadkach były one niskie i nie osiągały wartości granicznych w powietrzu. Im dalej od górnych źródeł zanieczyszczeń (główne przedsiębiorstwa przemysłowe w okręgu Raseiniai) tym wartości stężenia SO2 w powietrzu spadały. Średnie stężenia SO2 w powietrzu w rejonie Raseiniai nie osiągnęły dopuszczalnych wartości granicznych dla powietrza atmosferycznego (125 μg/m3) w okresie badania (w sierpniu 2016 r.). Wyniki badań wskazują, że najwyższe stężenie SO2 w powietrzu określone z użyciem porostów były w rejonie Raseiniai (41±2,0 µg/m3) i jego otoczeniu (Gabsiai (40±2,0 µg/m3), Andrušaičiai (41±2,0 µg/m3) i Gruzdiškės (39±2,0 µg/m3). Najwyższe stężenie SO2 w powietrzu zmierzone próbnikami pasywnymi było w rejonie Raseiniai (5,1±0,50 μg/m3) i jego otoczeniu (Gabšiai (4,0±0,39 μg/m3), Andrušaičiai (4,3±0,41 μg/m3) i Gruzdiškės (3,5 μg/m3). Najniższe stężenie SO2 zmierzono z zastosowaniem porostów w Nemakščiai i Viduklė (4±2,0 μg/m3 i 16±2,0 μg/m3) i 2,0±0,18 μg/m3 oraz 2,7±0,26 μg/m3 z zastosowaniem próbników pasywnych. Stwierdzono istotne zależności statystyczne między zmierzonymi stężeniami SO2 stosując obie metody. Zastosowano macierz korelacji Pearsona dla zmiennych w przy 95% przedziale ufności. Silna dodatnia korelacja (r = 0,84) między stężeniami SO2 mierzonymi za pomocą porostów i próbników pasywnych wskazuje, że porosty można stosować do oceny stężeń SO2 w powietrzu. Najniższe stężenia w badanych starostwach spowodowane są ich odległością od głównych zakładów przemysłowych i obiektów energetycznych

Adsorption Air Cleaning From Ozone

Not much has been written about air cleaning from ozone. The aim of this paper was to demonstrate the possibility of adsorption air cleaning from ozone. The second aim was to investigate the dependence of the efficiency of ozone removal from the air on the height of the adsorber layer and on concentrations of ozone, and to obtain empirical formulas for calculating the efficiency of ozone treatment. Equipment for air cleaning from ozone and nitrogen and sulphur dioxides is suggested

Heavy metal contamination in surface runoff sediments of the urban area of Vilnius, Lithuania

Surface runoff from urbanized territories carries a wide range of pollutants. Sediments in untreated runoff from direct discharge stormwater systems significantly contribute to urban waterway pollution. In this study, heavy metal (Pb, Zn, Cu, Cr, Ba, As and Fe) contamination in surface runoff sediments of the urban area of the city of Vilnius was investigated. The surface runoff sediment samples were collected from seven dischargers with the highest volume rate of water flow and concentrations of suspended solids. The geospatial analysis of the distribution of heavy metals shows that there are several active pollution sources supplying the dischargers with contaminated sediments. Most of these areas are located in the central part of the city and in old town with intense traffic. Principal components analysis and t-test results clearly depicted the significantly different chemical compositions of winter and autumn surface sediment samples. The sampling approach and assessment of results provide a useful tool to examine the contamination that is generated in urban areas, distinguish pollution sources and give a better understanding of the importance of permeable surfaces and green areas

Segregation of the Univalent X Chromosome in the Two-striped Planthopper Acanalonia bivittata

Chromosomes pair with their homologues to form a bivalent in meiosis I. The formation of bivalent chromosomes, alignment on the metaphase plate, and segregation during anaphase I is critical for correct cell division and production of haploid gametes, yet exceptions to the rule of bivalent formation exist. Here, we studied the segregation of the univalent X chromosome in the two-striped plant hopper Acanalonia bivittata (Hemiptera, Auchenorrhyncha). The species identification was verified through DNA barcoding, and the chromosome number is consistent with previously published karyotypes for the species. We show that A. bivittata male primary spermatocytes have a univalent X chromosome that displays independent and delayed segregation. Univalent segregation was observed to occur after that of the autosomes during early anaphase I and was associated with the loss of microtubule connections to one spindle pole. This work contributes to our knowledge of how chromosomes that lack a pairing partner can be segregated in an environment where they are surrounded by correctly segregating bivalents

Elastic ‘tethers’ connect separating anaphase chromosomes in a broad range of animal cells

We describe the general occurrence in animal cells of elastic components ("tethers") that connect individual chromosomes moving to opposite poles during anaphase. Tethers, originally described in crane-fly spermatocytes, exert force on chromosome arms opposite to the direction the anaphase chromosomes move. We show that they exist in a broad range of animal cells. Thus tethers are previously unrecognised components of general mitotic mechanisms that exert force on chromosomes and they need to be accounted for in general models of mitosis in terms of forces on chromosomes and in terms of what their roles might be